A number of amorphous materials (e.g., glass) and glass-ceramic compositions are known. Some amorphous materials can be consolidated via coalescing to provide articles, including articles having complex shapes (see, e.g., PCT publication No. 03/011776, published Feb. 13, 2003).
Various pressure-assisted consolidation methods are known in the ceramic art, and include hot-pressing, die-extrusion, hot-isostatic pressing, sinter-forging and variations of thereof. These consolidation methods are generally assisted by application of external force either directly through the use of punches as in hot-pressing, die-extrusion and sinter-forging, or indirectly through gas pressurization of a sealed container as in hot-isostatic pressing. In the latter method, the material to be consolidated is placed in a container (e.g., a metal container) and evacuated and sealed from an atmosphere. The sealed material is mechanical pressed thereby isostatically pressurizing the container with gas and causing the container to shrink.
Some amorphous compositions can be heat-treated to form glass-ceramics. The glass-ceramics tend to be more temperature resistant than the glass from which they are formed.
It is desirable to provide articles, including articles having complex shapes, comprising amorphous and glass-ceramics materials.